Time- and frequency-domain whirl-flutter analysis using a vortex particle method

Ethan Corle, Hao Kang, Matthew Floros, Sven Schmitz

Research output: Contribution to conferencePaper

Abstract

The method of using the viscous vortex particle method (VVPM) to conduct whirl-flutter stability analysis is evaluated on a 4-bladed, soft in-plane tiltrotor model using the Rotorcraft Comprehensive Analysis System (RCAS). For the first time, coupled VVPM/RCAS transient simulations are used to calculate whirl-flutter stability. In addition, a novel concept of linearizing VPM solutions by perturbing trimmed VPM inflow velocities with dynamic inflow (DI) states is studied to make linearized stability predictions via eigenanalysis. Comparisons are made between several different levels of fidelity in prediction capabilities and against experimental data. Time-domain stability predictions are shown to capture the physical features of rotor airloads and rotor-to-wing interactional aerodynamics. Linearization of VPM solutions using DI is shown to accurately capture rotor airloads but currently does not properly capture the rotor-towing interaction. Baseline results are presented using VPM and uniform inflow (UI) wake models. DI is demonstrated to be significantly more accurate than UI and makes linearized stability predictions similar to those made using VPM. Linearized VPM frequency and damping predictions are shown to be insensitive to vortex particle resolution; however, a reduction in damping is shown for particle resolutions less than 2% of the rotor span using time-domain transient analysis and needs further investigation.

Original languageEnglish (US)
StatePublished - Jan 1 2019
EventVertical Flight Society's 75th Annual Forum and Technology Display - Philadelphia, United States
Duration: May 13 2019May 16 2019

Conference

ConferenceVertical Flight Society's 75th Annual Forum and Technology Display
CountryUnited States
CityPhiladelphia
Period5/13/195/16/19

Fingerprint

Flutter (aerodynamics)
Vortex flow
Rotors
Damping
Linearization
Transient analysis
Aerodynamics

All Science Journal Classification (ASJC) codes

  • Aerospace Engineering
  • Control and Systems Engineering

Cite this

Corle, E., Kang, H., Floros, M., & Schmitz, S. (2019). Time- and frequency-domain whirl-flutter analysis using a vortex particle method. Paper presented at Vertical Flight Society's 75th Annual Forum and Technology Display, Philadelphia, United States.
Corle, Ethan ; Kang, Hao ; Floros, Matthew ; Schmitz, Sven. / Time- and frequency-domain whirl-flutter analysis using a vortex particle method. Paper presented at Vertical Flight Society's 75th Annual Forum and Technology Display, Philadelphia, United States.
@conference{d11e451c584c4157ba02bb4eacced18f,
title = "Time- and frequency-domain whirl-flutter analysis using a vortex particle method",
abstract = "The method of using the viscous vortex particle method (VVPM) to conduct whirl-flutter stability analysis is evaluated on a 4-bladed, soft in-plane tiltrotor model using the Rotorcraft Comprehensive Analysis System (RCAS). For the first time, coupled VVPM/RCAS transient simulations are used to calculate whirl-flutter stability. In addition, a novel concept of linearizing VPM solutions by perturbing trimmed VPM inflow velocities with dynamic inflow (DI) states is studied to make linearized stability predictions via eigenanalysis. Comparisons are made between several different levels of fidelity in prediction capabilities and against experimental data. Time-domain stability predictions are shown to capture the physical features of rotor airloads and rotor-to-wing interactional aerodynamics. Linearization of VPM solutions using DI is shown to accurately capture rotor airloads but currently does not properly capture the rotor-towing interaction. Baseline results are presented using VPM and uniform inflow (UI) wake models. DI is demonstrated to be significantly more accurate than UI and makes linearized stability predictions similar to those made using VPM. Linearized VPM frequency and damping predictions are shown to be insensitive to vortex particle resolution; however, a reduction in damping is shown for particle resolutions less than 2{\%} of the rotor span using time-domain transient analysis and needs further investigation.",
author = "Ethan Corle and Hao Kang and Matthew Floros and Sven Schmitz",
year = "2019",
month = "1",
day = "1",
language = "English (US)",
note = "Vertical Flight Society's 75th Annual Forum and Technology Display ; Conference date: 13-05-2019 Through 16-05-2019",

}

Corle, E, Kang, H, Floros, M & Schmitz, S 2019, 'Time- and frequency-domain whirl-flutter analysis using a vortex particle method' Paper presented at Vertical Flight Society's 75th Annual Forum and Technology Display, Philadelphia, United States, 5/13/19 - 5/16/19, .

Time- and frequency-domain whirl-flutter analysis using a vortex particle method. / Corle, Ethan; Kang, Hao; Floros, Matthew; Schmitz, Sven.

2019. Paper presented at Vertical Flight Society's 75th Annual Forum and Technology Display, Philadelphia, United States.

Research output: Contribution to conferencePaper

TY - CONF

T1 - Time- and frequency-domain whirl-flutter analysis using a vortex particle method

AU - Corle, Ethan

AU - Kang, Hao

AU - Floros, Matthew

AU - Schmitz, Sven

PY - 2019/1/1

Y1 - 2019/1/1

N2 - The method of using the viscous vortex particle method (VVPM) to conduct whirl-flutter stability analysis is evaluated on a 4-bladed, soft in-plane tiltrotor model using the Rotorcraft Comprehensive Analysis System (RCAS). For the first time, coupled VVPM/RCAS transient simulations are used to calculate whirl-flutter stability. In addition, a novel concept of linearizing VPM solutions by perturbing trimmed VPM inflow velocities with dynamic inflow (DI) states is studied to make linearized stability predictions via eigenanalysis. Comparisons are made between several different levels of fidelity in prediction capabilities and against experimental data. Time-domain stability predictions are shown to capture the physical features of rotor airloads and rotor-to-wing interactional aerodynamics. Linearization of VPM solutions using DI is shown to accurately capture rotor airloads but currently does not properly capture the rotor-towing interaction. Baseline results are presented using VPM and uniform inflow (UI) wake models. DI is demonstrated to be significantly more accurate than UI and makes linearized stability predictions similar to those made using VPM. Linearized VPM frequency and damping predictions are shown to be insensitive to vortex particle resolution; however, a reduction in damping is shown for particle resolutions less than 2% of the rotor span using time-domain transient analysis and needs further investigation.

AB - The method of using the viscous vortex particle method (VVPM) to conduct whirl-flutter stability analysis is evaluated on a 4-bladed, soft in-plane tiltrotor model using the Rotorcraft Comprehensive Analysis System (RCAS). For the first time, coupled VVPM/RCAS transient simulations are used to calculate whirl-flutter stability. In addition, a novel concept of linearizing VPM solutions by perturbing trimmed VPM inflow velocities with dynamic inflow (DI) states is studied to make linearized stability predictions via eigenanalysis. Comparisons are made between several different levels of fidelity in prediction capabilities and against experimental data. Time-domain stability predictions are shown to capture the physical features of rotor airloads and rotor-to-wing interactional aerodynamics. Linearization of VPM solutions using DI is shown to accurately capture rotor airloads but currently does not properly capture the rotor-towing interaction. Baseline results are presented using VPM and uniform inflow (UI) wake models. DI is demonstrated to be significantly more accurate than UI and makes linearized stability predictions similar to those made using VPM. Linearized VPM frequency and damping predictions are shown to be insensitive to vortex particle resolution; however, a reduction in damping is shown for particle resolutions less than 2% of the rotor span using time-domain transient analysis and needs further investigation.

UR - http://www.scopus.com/inward/record.url?scp=85070730065&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=85070730065&partnerID=8YFLogxK

M3 - Paper

ER -

Corle E, Kang H, Floros M, Schmitz S. Time- and frequency-domain whirl-flutter analysis using a vortex particle method. 2019. Paper presented at Vertical Flight Society's 75th Annual Forum and Technology Display, Philadelphia, United States.